The need for high performance grease compositions capable of supplying good wear properties over a broad temperature range and under extreme pressures is well established.
Specialized greases have been developed to meet the extra heavy duty performance requirements for mining and off-road construction equipment. These greases are employed in a wide range of applications where heavy pressures exist, including pins and bushings on bucket and loaders, shaker screens, crushers, conveyers and heavy equipment lubrication systems which involve pumping grease through long supply lines at low temperatures.
A key feature for remote applications is that the grease provides excellent low temperature pumpability and start-up. The grease should not soften and run under operating conditions encountered at higher temperatures so as to maintain an environmentally safe product, and yet, should as well exhibit good low temperature pumpability at lower temperatures. However, the features that afford warm weather adherence or stayability can impede low temperature performance and handling.
In addition, it is highly desirable that the grease provides excellent extreme pressure protection. This property is critical in that many of the lubrication points causing the most difficulty are pin and bushing assemblies which are subjected to oscillatory motion and shock loading. Such motion can result in loss of lubricant from the contact zone if the grease is overly fluid or insufficiently tacky, leading to early component failure and costly unplanned downtime.
Due to ever increasing demands for higher performance, it would be desirable to provide greases which exhibit improved lubrication properties, and in particular, improved low temperature pumpability and product adherence along with excellent extreme pressure performance.